Insect inhibitory proteins produced by Bacillus thuringiensis (Bt) bacterial species are known in the art. Certain Bt proteins can be used to control agricultural pests of crop plants by spraying agriculturally acceptable formulations containing one or more such proteins onto plants, coating seeds with a composition formulated to contain an insecticidally effective amount of such proteins, or by expressing the result effective one or more proteins in plants/seeds.
Only a few Bt proteins have been developed for use as transgenic traits for commercial use by farmers to control insect pests. Farmers rely on these proteins to provide a prescribed spectrum of pest control, and may continue to rely on broad spectrum chemistries in foliar and soil applications to control pests. Certain Lepidopteran insects, such as Agrotis species and Striacosta species, have proven to be particularly difficult to control using transgenic insecticidal traits currently in use including Cry1Ab, Cry1Ac, Cry1Fa, Cry2Ab, Cry2Ae, VIP3Aa, and various other Bt toxins that have been used less frequently. Hence, there is a need for insect inhibitory proteins that exhibit activity against a broader spectrum of insect pest species, and for use in toxins for use in overcoming resistance development of pests to existing pesticides, including toxins used currently in pest management systems.
This application describes a novel protein family, variants, and chimeric toxin protein constructs that each exhibit surprisingly efficacious insecticidal activity against Lepidoptera, particularly against Agrotis species pests, such as black cutworm.